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<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        var arr = [{ name: "李四", age: 20, gender: "男" }, { name: "王五", age: 21, gender: "男" }];
        var res = arr.map(
            function (item, key, arr) {
                return item.name;
            }
        )
        console.log(res);
    </script>
</body>

</html>